Locking device for throttle valves



April 21, 1942. R. H. sMlcKLE n 2,280,549

LOCKING `DEVICE FOR THROTTL-E VALVES Filed June 28, 1940 l IIIl 3j W@ g5 f M MIIIII K l 1. 27

, Y lNvENTOR Raymond/ Smic/Me HIS ATTORNEY I Patented Apr. 21, 1942 LOCKING DEVICE FOR THROT'ILE VALVES Raymond H.. Smickle, Belvidere, N. J., assignor Y to Ingersoll-Rand Company, New York, N. Y.,

a corporation of New Jersey Application June 28, 1940, SeralNo. 342,846

1 claim. (c1. 251-164) This invention relates to throttle valves, and more particularly to a locking device for throttle valves of the rotary type used for controlling the admission of pressure fluid into rock drills and similar machines.

The invention is intended more particularly for use on rock drills of the hand-held type. These tools and their accessories are handled by the operator Without assistance and, being of considerable weight, are usually moved from one drilling site to another by dragging them along the ground. In thus moving a tool about numerous injuries to operators have been causedwhen the throttle valve controlling the admission of pressure fluid into the rock drill was accidentally opened, by projections on the ground, and the drill thereby set in operation. In such event the Working implement may be violently ejected from the rock drill and the rotation mechanism may cause a rapid rotary movement of the casing of the rock drill and cause severe injury to the hand grasping it.

It is accordingly an object of the invention to preclude the possibility of accidentally setting the rock drill in operation.

Another object is to enable the throttle valve controlling the admission of pressure fluid in the rock drill to be conveniently locked in position.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawing accompanying this specification and in which similar reference numerals refer to similar parts,

Figure l is an elevation, partly in section, of a throttle valve assembly equipped with a locking device constructed in accordance with the practice of the invention and showing the locking elements in the locking positions,

Figure 2 is a plan view of the assembly,

Figure 3 is a transverse view taken through Figure 1 on the line 3-3, and

Figure 4 is a View similar to Figure l showing the locking elements in releasing positions.

Referring more particularly to the drawing, 20 designates a valve chest having a bore 2| to accommodate a throttle valve 22. a stem 23 of which projects from the bore 2| and carries a handle 24 whereby the throttle valve may be rotated.

The valve chest 2|! is shown as being in the form of a coupling member having a passage 25 extending entirely therethrough and controlled by the throttle valve 22, the latter having a transverse port 26 to aiord communication between the portions of the passage 25 lying on the opposite sides of the bore 2|. The ends of the valve chest are externally threaded sothat one end may be attached to a rock drill (not shown) and the other end to a conduit servingto convey pressure fluid from a source of supply to the valve chest.

The large end of the bore 2| is sealed .by a plug 21 threaded into the valve chest, and on the opposite side of the valve chest is a boss 28 thatencircles the bore 2| and has diametrically opposed notches 29 and 30 in its periphery.

The handle 24 comprisesa grip portion 3| that extends radially of the stem 23 and a hub 32 having an aperture 33 to receive the stem 23. A pin 34 extending through the hub 32 and the stem 23 secures the handle 24 to the throttle valve. v

In the opposite sides of the handle 24 are slots 35 and 36 that extend throughout the length of the handle and through the opposite sides'of the hub 32 to accommodate levers 31 and 38, respectively. Each lever is of L-shape and carries a, flange 39 suitably curved on its outer side to present a convenient gripping surface. The opposite ends of the levers are secured pivotally to the hub 32 by pins 4|! seated in the hub 32 and extending through the levers, On one side of the pins 4|) are arms 4| of the levers to engage the notches 29 and 30 in the closed position of the throttle valve 22.

To the end that the arms 4| may be held firmly in engagement With the notches in the boss 28 unaffected by the vibration incident to the operation of the rock drill to which the throttle valve f may be attached, the levers 3`| and 38 are provided, respectively, with opposed seating surfaces 42 and 43 that lie on the sides of the pins 40 opposite the arms 4|. The seating surfaces 42 and 43 lie on diametrically opposite sides of the hub 32, and in the portion of the hub lying between the seating surfaces is a bore 44 to receive plungers 45 that extend from opposite ends of the bore 44 to abut the seating surfaces. The plungers have cavities 46 in their opposed ends to receive a spring 41 serving to urge the levers totablish a desired degree of communication of the port 2B with the passage 25. The throttle valve will be held in this position by the frictional engagement between its tapered surface and that of the bore 2l and when it is desired to cut-off the flow of pressure fluid the throttle valve is rotated in either a right or left hand direction until the arms 4I coincide with the notches. The spring-pressed plungers will then actuate the levers to move the arms 4l into the notches for holding the throttle valve immovable.

As will be readily apparent, the throttle valve may be conveniently rotated in. either a right hand or a left hand direction for opening and closing it. This is highly desirable in devices of this character for the reason that it becomes necessary, at times, to cut-off the pressure uid supply to the rook drill quickly in situations where serious damage or injury might result ii the matter of the direction in which the throttle valve should be rotated must iirst be considered.

Another highly desirable advantage of the present invention is that the throttle valve will be securely locked in position so that when its handle engages aL protuberance on the Working surface there will be little or no danger of the valve being inadvertently opened.

If, as may happen upon occasion, one of the levers is accidentally tripped out of locking position, the other lever will remain in engagement with the boss 28 and With one of the levers in the disengaged position, the spring 41 will be addtionally compressed and in this Way the other lever Will be pressed firmly into locking engagement.

I claim:

A locking device for throttle valves, comprising a casing having a bore and notches on diametrically opposite sides of the bore, a rotary throttle valve in the bore, a handle for the throttle valve comprising a hub and a grip portion extending laterally of the hub, said handle having slots in the opposite sides thereof extending along the hub and the grip portion, levers in the slots, pins for pivotally securing the levers to the handle, latch portions on the levers lying on one side of the pins to engage the notches, seating surfaces on the levers opposed to each other and lying on the opposite side of the pins, plungers abutting the seating surfaces, and a spring interi-- posed between the plungers to maintain the latch portions in engagement with the notches.

RAYMOND H. SMICKLE. 

